Apparatus for reproducing electrical information



June 16, 1959 w. c. HUEBNER APPARATUS FOR REPRODUCING ELECTRICAL INFORMATION Filed March 29. 1956 2 Sheets-Sheet 1 .2) IEECT HIGH mnwrmL .SMOKE TUBE n. I E U R my z m s M L M ,m W 7 B. A 1:... W rm M mwwz 1 6 H w W w Q June 16, 1959 w. c. HUE'BNER 2,890,923

APPARATUS FOR REPRODUCING ELECTRICAL INFORMATION Filed March 29, 1956 2 Sheets-Sheet 2 United States Patent APPARATUS FOR REPRODUCING ELECTRICAL INFORMATION William C. Huebner, Mamaroneck, N.Y., assignor, by mesne assignments, to The Standard Register Company, Dayton, Ohio, a corporation of Ohio Application March 29, 1956, Serial No. 574,789

8 Claims. (Cl. 346-74) This invention relates to an apparatus for the direct reproduction of electrical information appearing as image information on a cathode ray tube and more particularly to reproduce the information to a reduced size from the information appearing on the cathode ray tube.

The terms light image or image information as used throughout the specification and claims are intended to specifically denote the image information derived from cathode ray tubes or television screens and the like produced by electrical information delivered thereto.

The terms print receiving materia and untreated print receiving material are used to define a material which has not been treated to give it special characteristics such as photographic, chemical or mechanical properties to aid in the receiving, developing, fixing or retaining of a reproduced image thereon. The material may be paper, cloth fabrics or other materials which are preferably but not necessarily in sheet or web form.

The term reproducing materia" includes any material capable of receiving an electrical charge or being ionized by any convenient method. The reproducing material may be further characterized as being capable of use in the form of divided and dispersed droplets or globules such as when provided in a cloudlike form.

The term cloud-like form is employed with the significance of the definition of cloud, namely a visible assemblage of solid or liquid particles in the air or in a gas as a cloud of smoke or of dust or of mist or of vapor.

It is therefore an object of the invention to provide an apparatus for immediately and directly reproducing electrical information on print receiving material through the derivation of light image or image information produced by the electrical information on the face of a cathode ray tube and projecting the light image onto a light-sensitive target positioned to influence an electric field and thereby control the flow of reproducing material introduced into the electric field for precipitating same on the print receiving material.

It is another object of the invention to provide an improved apparatus of the above-mentioned character in which the light-sensitive target is photoconductive and preferably is mounted between conductive layers with the outer conductive layer and its exposed surface provided with a plurality of minute projections and the conductive element being similarly provided with such projections.

It is still another object of the present invention to provide an improved apparatus of the kind mentioned for reproducing images to a reduced size utilizing a photoconductive target in an electric field to control the precipitation of reproducing material onto print receiving material, wherein a conductive element spaced from the target includes magnetic means for influencing the electric field.

Further and additional objects and advantages will become apparent hereinafter during the detailed descripf I w 1 Ce 2,890,923

tion of the embodiments of the invention which are to follow and which are illustrated in the accompanying drawings, wherein Fig. 1 is a diagrammatic representation illustrating and embodying a means of carrying out the invention;

Fig. 2 is a top plan view with portions broken away of the magnetic terminal shown in Fig. 1; and

Fig. 3 is a diagrammatic representation of a modified method of carrying out the invention.

Generally, the invention contemplates directly reproducing light images to a reduced size produced by electric information appearing as image formation on a cathode ray tube at high speeds in finished or final form on print receiving material through the utilization of a light-sensitive element as a target. The light-sensitive target is photoconductive and is spaced from a conductive element connected in circuit relationship therewith to a high voltage source to create an electric field therebetween. The light image produced by the electrical information is projected onto the light-sensitive target and is effective to cause a change in the conductivity or resistivity of the target and thereby influence the created electric field in accordance therewith. An image isolator acting as a shutter may be positioned intermediate the light-sensitive target and the conductive element. The reproducing material is introduced into the electric field adjacent the light-sensitive target or when the image isolator is employed intermediate the isolator and the target. The print receiving material is advanced through the electric field adjacent the conductive element in a time relationship with the projection of the light images onto the light sensitive target. The projection of the light images and the creation of the electric field are also controlled in a time relationship with the advancement of the print receiving material. The image isolator is further controlled to expose the spring receiving material momentarily during the existence of the light image and electric field to allow the reproducing material to be precipitated onto the print receiving material during that interval.

Now referring to Fig. 1 the novel reproducing apparatus will be described wherein a cathode ray tube 10 is shown with an image surface or face 11 thereof spaced to provide the image information as a light image to be projected through the lens system 12. The action of an electron beam 13 excites the phosphor on the face 11 to provide a light image. The light image emerging from the lens system 12 is caused to illuminate the light-sensitive target 14 cooperating with a conductive element 15 spaced therefrom and between which an electric field is created. Reproducing material in cloud-like form derived from a pressure conduit 16 may be passed between the elements 14 and 15 to an outlet or suction conduit 17. Print receiving material 18 is positioned between the elements 14 and 15 to receive the reproducing material propelled thereto by the electric field. An image isolator 20 is provided intermediate the print receiving material 18 and the path of flow of the reproducing material.

The cathode ray tube 10 is of conventional construction and accordingly the electrode structure in addition to a deflecting coil 21 is not considered necessary to the description of the invention, being well known in the art. Suffice it to say that the electron beam 13 generated in the tube 10 is influenced by the electrical information applied to the deflection coil 21 from an electrical information source 22, and in this instance is shown as a sine wave to represent the intelligence to be recorded. The electrical information source 22 may be any electrical source including a television signal. The inner surface of the tube face includes a phosphor which is Patented June 16, 1959 excited by the electron beam 13 to provide the image information on the outer surface of the tube face 11.

The lens system 12 is supported intermediate the cathode ray tube and the light-sensitive target 14. The lens system 12 is arranged to receive the images from the cathode ray tube 10 and to project them onto the adjacent face of the light-sensitive target 14. The size of the light image projected onto the light-sensitive target 14 is in this instance of a reduced size from the image information on tube face 11 and accordingly an aperture provided for the image isolator 20 is of a corresponding size. A shutter 23 may be provided for the lens system 12 and is opened and closed in timed relationship with the changes in the image information on the tube face 11, that is, the shutter will be opened when the image information is temporarily stopped.

The light-sensitive element or target 14 comprises a transparent mounting plate, in this instance shown as a glass plate 24, mounting a light sensitive, photoconductive, material 25 intermediate layers of conductive material 26 and 27. The conductive material 26 is a layer of silver deposited on the glass plate 24 in intimate contact therewith and having the photoconductive material, in this instance a selenium layer, deposited over the layer of silver. The layer of selenium is prepared with a proper proportion of alloys to render it light-sensitive. A photoconductive material, as is well known, varies in conductivity in response to the presence or absence of light. The change in conductivity takes the form of a change in resistance in elemental or discrete areas in proportion to the light received thereon and can be said to form. a pattern of the light. The resistance of the elemental areas decreases in response to light and they revert to their high resistance state upon the removal of the light.

The remaining layer of conductive material 27 is also a silver layer and is deposited in intimate contact with the opposite surface of the light-sensitive layer 25. This outer conductive layer 27 is provided with a plurality of minute relief buttons or projections 28 spaced over the entire outer surface of the layer. These projections 28 are provided on the conductive layer 27 by depositing a thin layer of a conductive material, in this instance the silver, over a porous cloth such as silk stretched over the layer 27 so as to allow the two layers of silver to adhere to one another through the infinitesimal openings in the cloth. These projections 28 are spaced over the layer 27 in rows and columns in a manner similar to that shown in my copending application Ser. No. 574,787, filed concurrently herewith and which is incorporated herein by reference. The projections 28 are provided to establish the lines of force of the electric field between the light-sensitive target 14 and the receiving element in a substantially straight line.

The conductive layers 26 and 27 along with the lightsensitive layer 25 are preferably arranged with a thickness so as not to reduce the light transmitting power of the mounting plate 24 less than 50%. The layers 25, 26 and 27 are mounted in intimate contact with one another and also with margins or can be said to be stepped to allow an electrical connection to be made to the de sired layer. Specifically, the layer 26 covers a larger area than the light-sensitive layer 25 which layer is in turn larger in area than the conductive layer 27.

The conductive or receiving element 15 is spaced from the light-sensitive target 14. The conductive element 15 comprises a flat electrical member 30, shown in this instance with a deposit of a conductive material 31 fixed to the element 15 and with a plurality of minute projections thereon. The projections for the conductive material 31 are arranged so that they will face the layer 27 of the target 14 and preferably are similarly disposed and arranged as on the layer 27 and in axial alignment therewith. If the print receiving material 18 is transparent or translucent it may be found desirable to place a light-sensitive layer between the conductive layer 30 and the conductive element 15 to further influence the electric field in accordance with the light image.

The conductive element 15 in this instance includes a magnetic attraction terminal 32 spaced on the opposite side of the electrical member 30 from the conductive material 31 provided to better concentrate the lines of force in straight lines created between the target 14 and the element 15. The use of the magnetic attraction terminal 32 is felt to be necessary when the image in formation is to be reduced in size so as to give finer and sharper detail of the image. The magnetic attraction terminal 32, as it is shown in Fig. 2, comprises a needle-point device 33 surrounded by an electromagnet 34. The electromagnet 34 is of a general toroidal shape with a substantially rectangular window to receive the needle-point device 33. The needlepoint device includes a plurality of needle-like elements 35, grouped in rows and columns substantially similar to the conductive projections 28. The elements 35 extend vertically from the electromagnet 34 in contact with the electrical member 30. The magnet 34 is energized by means of a DC. supply source 36 connected thereto by the lead wires 37 and 38, the latter of which is provided with a control switch 40.

The light-sensitive element 14 and the conductive element 15 are connected in a circuit relationship to a direct current high voltage source identified by the reference character 41. The positive terminal 42 of the high voltage source 41 is connected through a reversing switch 43 to the lead wire 44. A lead wire 44 is directly connected to the conductive layer 27 for the light-sensitive element 13 through a lead wire 45 provided with a variable resistor 46 in series circuit relationship therewith. The voltage of the source 41 is arranged to be sufiicient to create a high intensity electric field between the light element 14 and the conductive element 15 corresponding to the spacing between them and the characteristics of the light-sensitive layer 25.

An on-ofi switch 47 is also provided in series circuit relationship with the lead wire 45 and is arranged intermediate the resistor 46 and the lead wire 44. A capacitor 48 is also connected to the lead wire 45 intermediate the switch 47 and the lead wire 44 and which capacitor has its opposite terminal connected to ground. A negative terminal 50 for the high voltage source 41 is connected to ground and the electrical circuit through the light-sensitive element 14 and the conductive element 15 is completed by grounding the latter. This grounding connection is shown as a lead wire 51.

The print receiving material 18 is positioned intermediate the light-sensitive element 14 and the conductive element 15 and, in this instance, is shown adjacent the latter element. The print receiving material 18 is intermittently advanced between the elements 14 and 15 through the provision of feeding devices 52 and 53 spaced on opposite ends of the element 15 as shown. The feed ing devices 52 and 53 may be of any convenient construction and may be provided with pinwheels cooperating with marginal perforations in the print receiving material 17. It should be readily apparent that the intermittent advancement of the print receiving material 17 is accomplished in timed relationship with the delivery of the electrical signals to the cathode ray tube 10.

The reproducing material for the novel reproducing apparatus is introduced by means of the pressure conduit 16 spaced outwardly of and between the light-sensitive element 14 and the conductive element 15 adjacent the lateral edges thereof.

The reproducing material introduced between the elements 14 and 15 in this instance is in cloud-like form as hereinabove defined. When the reproducing material is introduced in cloud-like form, as in this embodiment, it

may be further characterized as smoke created by combustion of suitable materials such as powdered dyes, plastic powders or any other such material desired due to its color, intensity or ionization characteristics. The pressure conduit 16 is effective to cause the reproducing material to travel in a path between the elements 14 and 15 to the suction conduit 17 spaced on the opposite lateral edges thereof. The reproducing material travels in a path covering the image area of the light-sensitive element so as to come under the influence thereof. The suction conduit 17 is effective to collect or gather the residue of the reproducing material following the projection of the light images on the light element 14.

It has been found that an improved precipitation of the reproducing material results when it is given a charge to aid its migration or propulsion towards the print receiving material 17. Accordingly charging electrodes similar to the electrodes 54 and 55 are provided adjacent the outlet passage for the conduit 16. The electrodes 54 are shown as connected to ground while the electrodes 55 are connected to the high voltage source 41 by means of a lead wire 56 which is connected directly to the lead wire 44 for the voltage source.

The image isolator acts as a shutter to isolate the reproducing material from the print receiving material 18. Accordingly the image isolator 20 is positioned above the print receiving material 18 and below the path of the reproducing material. The image isolator 20 is mounted in any suitable manner to be continuously moved in timed relationship with the advancement of the print receiving material 18 and the delivery of the electrical signals to the tube 10. The image isolator 18 is provided with an aperture constructed and arranged thereon to pass the flow of the reproducing material to the print receiving material 18 migrated thereto under the influence of the electric field in a manner as described in my copending patent application Serial No. 574,787, filed concurrently herewith. The image isolator 20- may be provided with a plurality of apertures thereon when the delivery rate of the electrical signals is high. Accordingly it should be readily apparent that the image isolator 20 should be arranged in alignment with the tube 10 and moved in timed relationship with the delivery of the electrical signals thereto.

The image isolator 20 may be rotated by means of a pinion 57 suitably supported adjacent the toothed peripheral edge of the isolator, in this instance shown on the left-hand side thereof. The image isolator 20 is a thin metallic member and is provided with supporting surfaces comprising a plurality of bosses 58 spaced around the peripheral edge thereof.

The image isolator is also arranged to carry a charging wire (not shown) adjacent the leading edge of the aperture thereon. The charging wire extends across the isolator 20 on the surface adjacent the print receiving material 18 so as to contact and charge the latter as it sweeps over it. The charging wire is connected to the ground terminal of the high voltage source 41 through a lead wire 60 which may be provided with a suitable brush for completing the circuit thereto as is well known. The lead wire 60 is also provided with an on-off switch 61 connected in series circuit relationship therewith. The switch 61 is operated in timed relationship with the switches and 47.

It is thought that improved precipitation of the reproducing material results when in addition to charging the reproducing material, means for ionizing the same is provided. In this instance the reproducing material is ionized by means of short-wave radiant energy transmitted through the path of the reproducing material between the elements 14 and 15. A transmitting antenna 62 is arranged adjacent the outlet of the pressure conduit 16 and is connected by a suitable transmission line 63 to a short-wave generator 64. The short-wave generator 64 is arranged to provide radiant energy in the region around 200 megacycles and transmits the energy to a receiving antenna 65 positioned adjacent the inlet for the suction conduit 16. The receiving antenna 65 is suitably connected in a well known manner to a receiver 66 turned to the frequency of the generator 64.

With the above described apparatus in mind the steps leading to the final reproductions will become apparent. The reproductions depend upon the timed relationship of the delivery of the electrical signals to the tube 10 with the advancement of the print receiving material 18 which will, in turn, be synchronized or be arranged in a timed relationship with the opening and closing of the switches 40, 47 and 61 along with the shutter 23, when the latter is provided. The switches 40, 47, 61 and the shutter 23 are driven and controlled by a synchronous motor 67 or the like. The operation of the apparatus is arranged so that while the information for any one image is temporarily stationary on the tube face the print receiving material 18 is at rest and during this interval the image isolator 20 has been moved to a position where the aperture thereof is in alignment with the image focused onto the light-sensitive element 14. Substantially simultaneously with the alignment of the light image with the aperture the high voltage potential is applied across the elements 14 and 15 and to the charging wire through the closing of the switches 47 and 61. The combination of the light action and the high voltage stress is effective to cause the reproducing material to be migrated and propelled through the aperture for the image isolator 2 to be deposited on the print receiving material 18 immediately below the aperture. The flow of the reproducing material is defined by the electric field in proportion to the light intensity projected on the light element 14 so as to cause the immediate and direct reproduction of the light image on the print receiving material 18. Just prior to the change of the image information on the tube face the image isolator 20 is moved to cut off the flow of the reproducing material to the print receiving material 18. During this interval the print receiving material 18 is advanced to receive the next successive image information appearing on the face of the tube and the image isolator is brought to rest. It should be understood that the reproducing material is continuously passed between the elements 14 and 15 along with the transmission of the short-wave energy thereto.

Now referring to Fig. 3, a modified apparatus for reproducing images will be described. The apparatus shown herein is substantially similar to that previously described except that the reproducing material is introduced in a different and novel manner. In this instance the reproducing material is not introduced in a cloud-like form but is carried between the elements 14 and 15 by an endless belt 70. The belt 70 is preferably a transparent belt and a transparent plastic commercially identified as Saran Wrap is though to be satisfactory. Saran is a trademark for a thermoplastic resin comprising a copolymer of vinylidene chloride and vinyl chloride. The belt 70 is passed between rollers 71 and 72 spaced on opposite ends of the elements 14 and 15 and above the image isolator 20. The belt 70 passes from the roller 72 in a clockwise direction around the rollers '73, 74, 75 and 76 spaced around the conductive element 15, the latter roller being spaced upwardly from the roller 71. The reproducing material is applied to the belt 70 intermediate the rollers 76 and 71 and is put on the ribbon electronographically or by rollers. Any undesired static charge may be removed from the belt 70 in conventional manner when it is found to be necessary. A coating of reproducing material on the belt 70 is in this instance, shown as being applied by a spray 77. The reproducing material is then carried by the belt 70 through the elements 14 and 15 around the rollers 72 and into contact with an eraser or cleaning brushes 78 which are provided intermediate the roller 72 and the roller 73 to remove the excess or residue of the reproducing material from the belt so that it may be continuously used.

In this particular embodiment it is thought that the coating of the belt 70 with the reproducing material and passing it through the electric field will cause the reproducing material to be disassociated from the belt and propelled and migrated toward the print receiving material 18 under the influence of the electric field. It is thought that this manner of introducing the reproducing material provides improved reproductions since the background of the image will be more nearly controlled.

Although preferred forms of the invention have been described and illustrated herein it will be understood that the invention may be embodied in other forms coming within the scope and meaning of the appended claims.

Having thus described my invention, I claim:

1. In apparatus for reproducing information directly on print receiving material from a cathode ray tube having a phosphorescent screen comprising a light sensitive target spaced from said screen and including a photoconductive element positioned to receive a light image from said screen and to have substantially instantly a change in the electrical conductivity of discrete areas thereof in response to the configuration of said light image, means for positioning print receiving material spaced from said photoconductive element on the side thereof opposite to said cathode ray tube and defining an air gap therebetween, means for creating an electrostatic field in said air gap between said photoconductive element and said print receiving material, means for arranging the lines of force of said electrostatic field to be intercepted by said photoconductive element whereby said field is influenced in conformity to the configuration of said light image on said element, means for delivering electrical information to the cathode ray tube to produce a light image on the screen thereof, means for projecting the light image from said screen onto the photoconductive element of said light sensitive target at a size substantially reduced from the size appearing on said screen and in a predetermined timed relationship with the positioning of said print receiving material and the creation of said electrostatic field, and means for introducing reproducing material in said air gap to be acted upon by said electrostatic field and migrated thereby in finely divided form toward the print receiving material.

2. In apparatus for reproducing information directly on print receiving material from a cathode ray tube having a phosphorescent screen as defined in claim 1 and wherein said apparatus includes means in said air gap for exposing the light sensitive target to a predetermined area of the print receiving material and in a predetermined timed relationship with the positioning of said print receiving material and the creation of said electrostatic field in said air gap.

3. In apparatus for reproducing information directly on print receiving material from a cathode ray tube having a phosphorescent screen as defined in claim 1 and including means in said air gap effective to ionize said finely divided reproducing material.

4. In apparatus for reproducing information directly on print receiving material from a cathode ray tube having a phosphorescent screen as defined in claim 3 and wherein the means for ionizing the finely divided reproducing material includes means for transmitting short wave electrical radiations onto the air gap traversing the path taken by the reproducing material.

5. ln apparatus for reproducing information directly on print receiving material from a cathode ray tube having a phosphorescent screen as defined in claim 3 and including magnetic means effective to cause the lines of force of said electrostatic field to extend across the air gap in substantially straight lines.

6. In apparatus for reproducing images directly onto print receiving material from a cathode ray tube having a phosphorescent screen comprising a light sensitive target having a light transmitting portion mounting a photoconductive layer positioned to receive light images from said screen and to have substantially instantly a change in the electrical resistivity thereof in response to the configuration of said light images, a conductive element spaced from said light sensitive target on the side opposite to said cathode ray tube and defining an air gap therebetween, a source of relatively high voltage effec tive between said photoconductive layer and said conductive element to provide a high intensity electrostatic field in said air gap, means for positioning print receiving material in said air gap and adjacent said conductive element, means for isolating and exposing predetermined areas of said positioned print receiving material from and to said target in a predetermined time relation with the creation of said electrostatic field, means for de livering electrical information to the cathode ray tube to produce light images on the screen thereof, lens means intermediate said cathode ray tube and said light sensitive target for receiving light images from the screen of said tube and effective to project said images onto the photoconductive layer of said light sensitive target at a size substantially reduced from the size appearing on said screen and in a predetermined time relationship with the positioning of said print receiving material and the creation of said electrostatic field, and means for introducing reproducing material in cloud-like form into said air gap and intermediate the light sensitive target and said isolating means, said reproducing material being acted upon by the lines of force of said electrostatic field and migrated thereby toward the print receiving material. to produce thereon in final finished form a reproduction of the light images projected on the screen of said cathode ray tube.

7. In apparatus for reproducing images directly on print receiving material from a cathode ray tube having a phosphorescent screen as defined in claim 6 and wherein magnetic means adjacent the conductive element is arranged to influence the lines of force of said electrostatic field in said air gap.

8. In apparatus for reproducing information directly on print receiving material from a cathode ray tube having a phosphorescent screen comprising a light sensitive target spaced from said screen and including a photoconductive element positioned to receive a light image from said screen and to have substantially instantly a change in the electrical conductivity of discrete areas thereof in response to the configuration of said light image, means for positioning print receiving material spaced from said photoconductive element on the side thereof opposite to said cathode ray tube and defining an air gap therebetween, means for creating an electrostatic field in said air gap between said photoconductive element and said print receiving material, means for arranging the lines of force of said electrostatic field to be intercepted by said photoconductive element whereby said field is influenced in conformity to the configuration of said light image on said element, means for delivering electrical information to the cathode ray tube to produce a light image on the screen thereof, means for projecting the light image from said screen onto the photoconductive element of said light sensitive target at a size substantially reduced from the size appearing on said screen and in a predetermined timed relationship with the positioning of said print receiving material and the creation of said electrostatic field, and means for introducing reproducing material in the form of a coating on a belt into said air gap between said photoconductive element and said print receiving material to be acted upon by said electrostatic field and disassociated thereby from said belt and migrated toward the print receiving material to deposit and form thereon the finished reproduction of said information.

References Cited in the file of this patent UNITED STATES PATENTS 5 Hewitt May 27, 1919 Selenyi Aug. 11, 1931 Jacob Oct. 21, 1952 Huebner Apr. 20, 1954 10 MacGrifl Nov. 20, 1956 

